Fuel oil supply nozzle method for manufacturing discharge pipe thereof

ABSTRACT

A fuel oil supply nozzle includes a cylindrical discharge pipe and an anchor spring mounted on an outer circumference surface of the discharge pipe. The anchor spring is a spring wire in a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of an axis is situated inside, and is mounted on the discharge pipe in a state in which the contact portion is pit into close contact with the outer circumference surface of the discharge pipe by a contracting force reducing the inside diameter of the spring.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fuel oil supply nozzle mounted on an end of a fuel oil supply hose of a measuring unit for supplying fuel oil and a method for manufacturing a discharge pipe for the fuel oil supply nozzle.

2. Description of the Related Art

Conventionally, to supply fuel oil to an automobile through a fuel oil supply nozzle, a fuel oil is supplied with a discharge pipe mounted on the tip of a nozzle body into the fuel oil supply port of an automobile. To prevent the fuel oil supply nozzle from dropping off from the fuel oil supply port of the automobile during the fuel oil is supplied, the fuel oil supply nozzle has an anchor spring to be mounted on its discharge pipe. The discharge pipe is formed with a slightly bent shape on a side close to the nozzle body so as to be easily inserted into the fuel oil supply port of an automobile and is mounted with the anchor spring formed using a wire made of a spring material into a spiral shape in an area from a position close to the nozzle body of the discharge pipe to a position slightly closer to a tip than a middle position.

A spring formed of a spring wire into a circular cross section is generally used as an anchor spring to be mounted on the discharge pipe in this manner, so the contact area of the anchor spring with the outer circumference surface of the discharge pipe becomes small and hence a frictional force becomes small, which raises a possibility that the anchor spring will come off from the discharge pipe during a fuel oil is supplied and will drop into the fuel oil supply port of an automobile. For this reason, conventionally, to prevent an anchor spring 2 mounted on the outer circumference surface of the discharge pipe 1 from dropping off, for example, as shown in FIG. 15, a protrusion 3 is welded to the outer circumference surface of the discharge pipe 1 mounted with the anchor spring 2. However, such a protrusion 3 raises a possibility that the protrusion 3 will be put into contact with the fuel oil supply port of the automobile during the fuel oil is supplied and hence will be worn or broken to cause the anchor spring 2 to drop off. Moreover, to weld the protrusion 3 to the outer circumference surface of the discharge pipe 1 not only increases cost but also is likely to impair a commercial value from outward appearance. The present applicant discloses a technology relating to a fuel oil supply nozzle such that an anchor spring is mounted on the outer circumference surface of a discharge pipe at a position separate from a nozzle body so as to make the body part of the fuel oil supply nozzle less easily contact the fuel oil supply port of the automobile and that a ring is further fixed to the discharge pipe so as to prevent the anchor spring from dropping off (refer to Japanese Patent Application Laid-Open (JP-A) No. 11-29200 (pages 2 and 3, FIG. 1)).

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-mentioned circumstances. It is the object of the present invention to provide a fuel oil supply nozzle that can surely prevent an anchor spring to be mounted on a discharge pipe from dropping off and a method for manufacturing a discharge pipe for the fuel oil supply nozzle.

To achieve the object described above, in accordance with a first aspect of the invention, there is provided a fuel oil supply nozzle including: a nozzle body that has an inflow port formed on one end side, the inflow port being connected to an end portion of a fuel oil supply hose via which fuel oil is supplied, has an outflow port formed on the other end side, and has a valve mechanism for flowing the fuel oil, the valve mechanism being disposed in a flow passage formed between the inflow port and the outflow port; a cylindrical discharge pipe having one end side connected to the outflow port of the nozzle body; and an anchor spring to be mounted on an outer circumference surface of the discharge pipe, wherein the anchor spring is formed using a spring wire in a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of the axis of the spiral wire is situated inside, and is mounted in a state in which the contact portion is put into close contact with the outer circumference surface of the discharge pipe by a contracting force reducing the inside diameter of the spring. Since the anchor spring is mounted in a state in which the contact portion is put into close contact with the outer circumference surface of the discharge pipe by the contracting force reducing the inside diameter of the spring, it is possible to surely prevent the anchor spring to be mounted on the discharge pipe from coming and dripping off.

In a second aspect of the invention, the contact portion of the anchor spring may be formed with a concave surface and may have both end sides of its width formed with protrusions pressed onto the outer circumference surface of the discharge pipe. Since the protrusions of the contact portion of the anchor spring are pressed onto the outer circumference surface of the discharge pipe, it is possible to prevent the anchor spring from coming and dropping off.

In a third aspect of the invention, the contact portion of the anchor spring may be formed with a flat surface pressed onto the outer circumference surface of the discharge pipe. Since the contact portion of the anchor spring is formed with the flat surface and is put into surface contact with the outer circumference surface of the discharge pipe to increase a frictional force, it is possible to prevent the anchor spring from coming and dropping off.

In accordance with a fourth aspect of the invention, there is provided a method for manufacturing a discharge pipe for a fuel oil supply nozzle, the method including the steps of: forming an anchor spring by winding a spring wire in a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of the axis of the spiral wire is situated inside; expanding an inside diameter on the contact portion side against the contracting force of the anchor spring; inserting a straight discharge pipe into an inside diameter side of the expanded anchor spring and thereafter releasing the contracting force to press and mount the anchor spring on an outer circumference surface of the discharge pipe; and bending the discharge pipe mounted with the anchor spring. Accordingly, it is possible to mount the anchor spring on the discharge pipe by applying the contracting force of the spring to the outer circumference surface of the discharge pipe.

In a fifth aspect of the invention, the step of expanding the inside diameter of the anchor spring includes fixing one end side of the anchor spring and rotating the other end side against the contracting force of the spring. Since one end side of the anchor spring is fixed and the other end side is rotated against the contracting force of the spring, it is possible to insert the discharge pipe into the inside diameter side of the anchor spring.

In a fuel oil supply nozzle including: a nozzle body that has an inflow port formed on one end side, the inflow port being connected to an end portion of a fuel supply hose via which fuel oil is supplied, has an outflow port formed on another end side, and has a valve mechanism for flowing the fuel oil, the valve mechanism being disposed in a flow passage formed between the inflow port and the outflow port; a cylindrical discharge pipe having one end side connected to the outflow port of the nozzle body; and an anchor spring to be mounted on an outer circumference surface of the discharge pipe, the anchor spring is formed using a spring wire in a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of the axis of the spiral wire is situated inside, and is mounted in a state in which the contact portion is put into close contact with the outer circumference surface of the discharge pipe by a contracting force reducing the inside diameter of the spring. Thus, the anchor spring may be mounted in a state in which the contact portion is put into close contact with the outer circumference surface of the discharge pipe by the contracting force reducing the inside diameter of the spring. Therefore, it is possible to surely prevent the anchor spring to be mounted on the discharge pipe from coming and dripping off.

Moreover, the method for manufacturing a discharge pipe for a fuel oil supply nozzle includes the steps of: forming an anchor spring by winding a spring wire in a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of the axis of the spiral wire is situated inside; expanding an inside diameter on the contact portion side against the contracting force of the anchor spring; inserting a straight discharge pipe into an inside diameter side of the expanded anchor spring and thereafter releasing the contracting force to press and mount the anchor spring on an outer circumference surface of the discharge pipe; and bending the discharge pipe mounted with the anchor spring. Therefore, it is possible to mount the anchor spring on the discharge pipe by applying the contracting force of the spring to the outer circumference surface of the discharge pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a fuel oil supply nozzle of an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a discharge pipe mounted with an anchor spring of an embodiment of the invention.

FIG. 3 is an enlarged perspective view of a wire part for an anchor spring of an embodiment of the invention.

FIG. 4 is a diagram illustrating a method for manufacturing the discharge pipe mounted with an anchor spring of an embodiment of the invention.

FIG. 5 is a diagram illustrating a method for mounting an anchor spring of an embodiment of the invention on a discharge pipe by the use of a mounting tool.

FIG. 6 is a diagram illustrating a state in which the fuel oil supply nozzle of an embodiment of the invention is inserted into the fuel oil supply port of the automobile to supply fuel oil.

FIG. 7 is a graph showing a comparison of the mounting strength of the anchor spring between an embodiment of the invention and conventional anchor springs.

FIG. 8 is a front view of a fuel oil supply nozzle of another embodiment of the invention.

FIG. 9 is an enlarged perspective view of a wire for an anchor spring of another embodiment of the invention.

FIG. 10 is an enlarged perspective view of a wire for an anchor spring of another embodiment of the invention.

FIG. 11 is an enlarged perspective view of a wire for an anchor spring of another embodiment of the invention.

FIG. 12 is a diagram illustrating an anchor spring to be mounted on a discharge pipe of another embodiment of the invention.

FIG. 13 is a diagram illustrating an anchor spring to be mounted on a discharge pipe of another embodiment of the invention.

FIG. 14 is a diagram illustrating an anchor spring to be mounted on a discharge pipe of another embodiment of the invention.

FIG. 15 is a diagram illustrating a state in which a conventional anchor spring is mounted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described specifically with reference to embodiments. FIGS. 1 to 7 are diagrams illustrating a fuel oil supply nozzle of an embodiment of the present invention and a method for manufacturing a discharge pipe for the fuel oil supply nozzle. FIG. 1 is a front view of the fuel oil supply nozzle. FIG. 2 is an enlarged cross-sectional view of a discharge pipe mounted with an anchor spring. FIG. 3 is an enlarged perspective view of a wire part for the anchor spring. FIG. 4 is a diagram illustrating a method for manufacturing the discharge pipe mounted with the anchor spring. FIG. 5 is a diagram illustrating a method for mounting the anchor spring on the discharge pipe by the use of a mounting tool. FIG. 6 is a diagram illustrating a state in which the fuel oil supply nozzle is inserted into the fuel oil supply port of an automobile to supply fuel oil. FIG. 7 is a graph showing a comparison of the mounting strength of the anchor spring between the embodiment and conventional anchor springs.

A fuel oil supply nozzle 10 of the embodiment of the invention is a part inserted into the fuel oil supply port of an automobile and to supply fuel oil supplied via a fuel oil supply hose 19 from a measuring unit. The fuel oil supply nozzle 10 is composed of a nozzle body 11, a discharge pipe 12 mounted on the nozzle body 11, and an anchor spring 13 to be mounted on the outer circumference surface of the discharge pipe 12.

In the nozzle body 11, an inflow port 14 connected to such an end of the fuel oil supply hose 19 that is close to the measuring unit for supplying the fuel oil is formed on one end side thereof, and an outflow port 15 is formed on the other end side, and a valve mechanism having a main valve or an automatic closing valve mechanism or the like is disposed in a flow passage formed between the inflow port 14 and the outflow port 15, and the outer circumference portion near the inflow port 14 is formed with a grip part 16 gripped by an operator with a hand when the operator supplies a fuel oil. The nozzle body 11 is provided with an opening and closing lever 17 operatively connected to the valve mechanism and a latch 18 that pulls the opening and closing lever 17 to hold the valve mechanism in an open state.

The discharge pipe 12 is made of a pipe material formed with a cylindrical shape, has its one end connected to the outflow port 15 of the nozzle body 11, has its other end opened as the outflow port of the fuel oil, and has its middle portion bent in a gentle arc shape. In this embodiment, the discharge pipe 12 may be made of a pipe material made of material of aluminum or the like and having an outer diameter of 21 mm and a total length of 195 mm, for example. For another example, a pipe having an outer diameter of 25 mm and a total length of 195 mm may be used as the discharge pipe 12.

The anchor spring 13 is formed using a spring wire 20 in a spiral shape and is mounted on the outer circumference surface of the discharge pipe 12. The spring wire 20 is formed of an ordinary spring metal material. As for the shape of the spring wire 20, as shown in FIGS. 2 and 3, one side with respect to the axial of the wire is formed, as a contact portion 22 having a width, with a concave surface 22 a formed by slightly depressing the middle part, and both end sides of the concave surface 22 a are formed with slightly protruding protrusions 22 b and 22 b, and the other side other than the contact portion 22 is formed with a cylindrical surface 21. The spring wire 20 may be made using a spring having its outer diameter at the cylindrical surface 21 of approximately 2.6 mm, for example, and the shape of the contact portion 22 may be made by forging or the like. The anchor spring 13 yet to be mounted on the discharge pipe 12 is formed using the spring wire 20 in a spiral shape in such a way that the concave surface 22 a and the protrusions 22 b and 22 b, which construct the contact portion 22 having a width, are situated on the inside surface side and that its inside diameter is slightly smaller than the outside diameter of the discharge pipe 12. For example, as the anchor spring 13 to be mounted on the discharge pipe having an outer diameter of 21 mm, an anchor spring that is formed with an inside diameter of approximately 20 mm yet to be mounted is used. Moreover, as the anchor spring 13 to be mounted on the discharge pipe 12 having an outer diameter of 25 mm, an anchor spring that is formed with an inside diameter of approximately 24 mm yet to be mounted is used. In the anchor spring 13, for example, one end portion 23 is formed using the spring wire 20 approximately three turns close to each other in a spiral shape is formed at a portion close to the inflow port 15, a middle portion in which the spring wire 20 at given spacing in a spiral shape in the middle, and an end portion 24 is formed using the spring wire 20 is wound approximately two turns close to each other in a spiral shape is formed at the other end. The length between the end portions 23 and 24 of the anchor spring 13 is formed, for example, into approximately 85 mm for the anchor spring 13 to be mounted on the discharge pipe 12 having an outside diameter of 21 mm. For the anchor spring 13 to be mounted on the discharge pipe 12 having an outside diameter of 25 mm, the length is formed with approximately 115 mm.

Next, a method for manufacturing the discharge pipe 12 mounted with the anchor spring 13 will be described specifically. As shown in FIG. 4(1), first, as the anchor spring 13 is used a spring formed with an inside diameter of a1 smaller than the outside diameter of the discharge pipe 12. That is, as described above, for example, a spring that is formed with an inside diameter of approximately 20 mm before it may be mounted is used as the anchor spring 13 to be mounted on the discharge pipe 12 having an outside diameter of 21 mm, and a spring that is formed with an inside diameter of approximately 24 mm before it is mounted may be used as the anchor spring 13 to be mounted on the discharge pipe 12 having an outside diameter of 25 mm. Next, as shown in FIG. 4(2), the anchor spring 13 having the inside diameter of a1, is expanded so as to have an inside diameter of a2 slightly larger than the outside diameter of the discharge pipe 12 against the contracting force of the spring. Subsequently, as shown in FIG. 4(3), the straight discharge pipe 12 is inserted into the anchor spring 13 expanded into the inside diameter of a2 and then the expanded spring is released to press and mount the contact portion 22 on the surface of the discharge pipe 12 by the contracting force of the spring.

A method for expanding the anchor spring 13 to mount it on the discharge pipe 12 will be described in detail with reference to FIG. 5. To mount the anchor spring 13 on the discharge pipe 12, as shown in FIG. 5, a mounting tool having a support part 25 for supporting the one end portion 23 of the anchor spring 13 and a rotation part 26 for supporting and rotating the other end portion 24 against the spring force of the anchor spring. The support part 25 has an opening 25 a formed on one side, the opening 25 a having an inside diameter of c slightly larger than the outside diameter of b of the discharge pipe 12. The support part 25 has an opening 25 b formed on the other side, into which the end portion 24 of the anchor spring 13 is inserted therethrough and which has an inside diameter large enough for the anchor spring 13 not to contact the support part 25 even when the anchor spring 13 is expanded. Moreover, the support part 25 has a support portion 25 c, to which an end surface 23 a of the anchor spring 13 is pressed, is formed on the opening 25 b side. The spring wire close to the end portion 23 of the anchor spring 13 is winded starting from the end surface 23 a. The rotation part 26 is formed with the same shape as the support part 25: that is, the rotation part 26 has an opening 26 a formed on one side, the opening 26 a having an inside diameter of c; the rotation part 26 has an opening 26 b formed on the other side, the opening 26 b into which the end portion 24 of the anchor spring 13 is inserted and having an inside diameter d; and the rotation part 26 has a support portion 26 c formed on the opening 26 b side, the support portion 26 c to which an end surface 24 a of the anchor spring 13 is pressed, the spring wire close to the end portion 24 of the anchor spring 13 is winded terminating at the end surface 24 a. To expand the inside diameter of the anchor spring 13 by the use of the support part 25 and the rotation part 26, the support part 25 into which the end portion 23 of the anchor spring 13 is inserted is fixed and the rotation part 26 into which the end portion 24 of the anchor spring 13 is inserted is rotated against the spring force in a direction opposite to a direction in which the anchor spring 13 is wound into a spiral shape, whereby the inside diameter of the anchor spring 13 is expanded. That is, the anchor spring 13 having the inside diameter of a1 as shown in FIG. 4(1), is expanded, so as to have an inside diameter of a2 slightly larger than the outside diameter of the discharge pipe 12 as shown in FIG. 4(2), against the contracting force of the spring. In this state in which the inside diameter of the anchor spring 13 is expanded, the discharge pipe 12 formed in a straight shape is inserted through the inside diameter side of the anchor spring 13 from the opening 25 a side of the support part 25 and is then into the opening 26 a of the rotation part 26. Subsequently, the rotation of the rotation part 26 is returned in a direction toward the original position in a state in which the discharge pipe 12 is inserted into the support part 25, the inside diameter of the expanded anchor spring 13, and the rotation part 26, whereby as shown in FIG. 4(3), the anchor spring 13 is reduced in the inside diameter by the contracting force of the expanded anchor spring 13 and hence may be pressed and mounted on the surface of the discharge pipe 12 having the outside diameter of b by the contracting force of the spring.

Subsequently, the straight discharge pipe 12 mounted with the anchor spring 13 as shown in FIG. 4(3) is slightly bent at the substantially middle portion of the discharge pipe 12 where the anchor spring 13 is mounted by the use of a specified bending tool as shown in FIG. 4(4). The discharge pipe 12 mounted with the anchor spring 13 and formed in this manner is mounted on the outflow port 15 of the nozzle body 11.

In the fuel oil supply nozzle 10 constructed in the above-mentioned manner, the anchor spring 13 is formed using winding the spring wire 20 having a contact portion 22, which is formed on one side with respect to the axial of the spring wire 13 with a width, and winding the spring wire 20, into a spiral shape in such a way that the contact portion 22 is situated on the inside diameter side of the spring wire 20 and that its inside diameter is slightly smaller than the outside diameter of the discharge pipe 12. Then, the anchor spring 13 is mounted on the outer circumference surface of the discharge pipe 12 in a state in which its inside diameter side is expanded, the inside diameter side having the contact portion 22 formed thereon. The contact portion 22 on the inside diameter side of the anchor spring 13 wound in the spiral shape has the contracting force of the spring to reduce the inside diameter applied thereto, thereby being pressed onto the outer circumference surface of the discharge pipe 12. Moreover, the contact portion 22 on the inside diameter side of the anchor spring 13 is formed with the slightly depressed concave surface 22 a, and the protrusions 22 b and 22 b formed on both end sides of the width of the depressed concave surface 22 a are pressed onto the outer circumference surface of the discharge pipe 12. Thus, the anchor spring 13 is applied with the contracting force of the spring to the outer circumference surface of the discharge pipe 12 and presses the protrusions 22 b, 22 b onto the outer circumference surface of the discharge pipe 12. Accordingly, the anchor spring 13 can increase a contact force to the outer circumference surface of the discharge pipe 12 and hence can surely be prevented from coming and dropping off. Moreover, since the discharge pipe 12 mounted with the anchor spring 13 is slightly bent, the anchor spring 13 may be further prevented from coming and dropping off.

Moreover, according to the method for manufacturing a discharge pipe for a fuel oil supply nozzle of the above-mentioned construction, the anchor spring 13 yet to be mounted on the discharge pipe 12 is previously formed in such a way that its inside diameter, into which the contact portion 22 is formed, is smaller than the outside diameter of the discharge pipe 12. Next, when the anchor spring 13 is mounted on the discharge pipe 12, the one end portion 23 of the anchor spring 13 is supported by the support part 25 so as not to rotate and the other end portion 24 is rotated by the rotation part 26 against the spring force in a direction opposite to a direction in which the anchor spring 13 is wound in the spiral shape, whereby the inside diameter of the anchor spring 13 is expanded so as to be larger than the outside diameter of the discharge pipe 12. Subsequently, the discharge pipe 12 formed in a straight shape is inserted through the inside diameter side of the expanded anchor spring 13, and then the rotation part 26 is rotated so as to return to the direction toward the original position to reduce the inside diameter of the anchor spring 13 by the contracting force of the spring to thereby press the anchor spring 13 onto the outer circumference surface of the discharge pipe 12. Subsequently, the discharge pipe 12 mounted with the anchor spring 13 is slightly bent at the substantially middle portion thereof by the use of a specified bending tool. By the method for manufacturing the discharge pipe 12 for the fuel oil supply nozzle like this, the anchor spring 13 may be mounted in a state in which the contracting force for reducing the inside diameter of the anchor spring 13 is applied to the outer circumference surface of the discharge pipe 12.

Next, the results of comparisons of the extracting force of the anchor spring 13 according to this embodiment from the discharge pipe 12 and the extracting force of conventional anchor springs from discharge pipes will be described with reference to FIG. 7. This graph shows the results of comparisons of the extracting force of the anchor spring 13 which, as described in this embodiment, was formed with an inside diameter of 20 mm and a length of 85 mm before it was mounted and which was mounted on the straight discharge pipe 12 having an outside diameter of 21 mm in a state in which the anchor spring 13 was expanded and the extracting forces of a conventional anchor spring made of a spring wire of circular cross section and having no welded portion, a conventional anchor spring having a welded portion, and a conventional anchor spring reduced in inside diameter. In the anchor spring 13 of this embodiment, the extracting force was 800 kg at the maximum value, approximately 150 kg at the minimum value, and 400 kg at the average value, whereas in the conventional anchor springs, all of the maximum values, the minimum values and the average values of the extracting forces were smaller than 100 kg.

In the fuel oil supply nozzle 10 of the invention, as shown in FIG. 8, the portion of the outflow port 15 of the nozzle body 11 may be provided with a splash guard 29 for preventing fuel oil from splashing.

Next, the spring wires of the other embodiments will be described with reference to FIG. 9 to FIG. 11. A spring wire 30 shown in FIG. 9 has one side with respect to the axial of the wire formed with a flat surface 32 a as a contact portion 32 having a width. The spring wire 30 has the other side other than the contact surface 32 formed with a cylindrical surface 31. When an anchor spring is formed by the use of the spring wire 30 formed with this shape, the contact portion 32 formed with the flat surface 32 a is put into surface contact with the outer circumference surface of the discharge pipe 12 mounted with the anchor spring to increase the frictional force to thereby prevent the anchor spring from coming and dropping off. A spring wire 33 shown in FIG. 10 has one side with respect to the axial of the wire formed with a concave surface 35 a as a contact portion 35 having a width, the concave surface 35 a being slightly depressed in the middle portion and both end sides of the concave surface 35 a being formed with slightly protruding protrusions 35 b and 35 b. Moreover, the spring wire 33 has the other side other than the contact portion 35 formed with a polygonal surface 34. When the protrusions 35 b and 35 b are pressed onto the outer circumference surface of the discharge pipe 12 by using the spring wire 33 like this, the anchor spring may be similarly prevented from coming and dropping off. A spring wire 36 shown in FIG. 11 has one side with respect to the axial of the wire formed with a flat surface 38 a as a contact portion 38 having a width and has the other side other than the contact portion 38 formed with an polygonal surface 37. When an anchor spring is formed by the use of the spring wire 36 formed with this shape, in the same way as with the spring wire 30 shown in FIG. 9, the frictional force is made large and hence the anchor spring may be prevented from coming and dropping off.

Next, the anchor springs of the other embodiments will be described with reference to FIG. 12 to FIG. 14. An anchor spring 40 shown in FIG. 12 has an end portion 41 formed at a portion close to the inflow port 15 by winding the spring wire three turns into a spiral shape and has an end portion 42 formed at the other end side by winding the spring wire one turn into a spiral shape. An anchor spring 43 shown in FIG. 13 has an end portion 44 formed at a portion close to the inflow port 15 by winding the spring wire four turns into a spiral shape and has an end portion 45 formed at the other end side by winding the spring wire three turns into a spiral shape. An anchor spring 46 shown in FIG. 14 has an end portion 47 formed at a portion close to the inflow port 15 by winding the spring wire four turns into a spiral shape and has an end portion 48 formed at the other end side by winding the spring wire two turns into a spiral shape. The above-mentioned respective anchor springs 40, 43, and 46 have the end portions formed on both end sides thereof by winding the spring wire in close contact with each other and in the spiral shape, the respective end portions differing from each other in the number of turns of the spring wire. To prevent the anchor spring from coming and dropping off, the number of turns of the spring wire at the end portion may be selected optionally when necessary.

The sizes and materials of the discharge pipe 12 and the spring wires 20, 30, 33, and 36 in the above-mentioned respective embodiments are examples and the shapes of the contact portions 22, 32, 35, and 38 are not limited to the embodiments.

The present invention may be applied to a fuel oil supply nozzle mounted on the end portion of a fuel oil supply hose of a measuring unit for supplying fuel oil and a method for manufacturing a discharge pipe for the fuel oil supply nozzle. 

1. A fuel oil supply nozzle comprising: a nozzle body that has an inflow port formed on one end side, the inflow port being connected to an end portion of a fuel oil supply hose via which fuel oil is supplied, has an outflow port formed on the other end side, and has a valve mechanism for flowing the fuel oil, the valve mechanism being disposed in a flow passage formed between the inflow port and the outflow port; a cylindrical discharge pipe having one end side connected to the outflow port of the nozzle body; and an anchor spring to be mounted on an outer circumference surface of the discharge pipe, wherein the anchor spring is formed using a spring wire into a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of the axis of the spiral wire is situated inside, and is mounted in a state in which the contact portion is put into close contact with the outer circumference surface of the discharge pipe by a contracting force reducing the inside diameter of the spring.
 2. The fuel oil supply nozzle according to claim 1, wherein the contact portion of the anchor spring is formed with a concave surface and has both end sides of its width with protrusions pressed onto the outer circumference surface of the discharge pipe.
 3. The fuel oil supply nozzle according to claim 1, wherein the contact portion of the anchor spring is formed with a flat surface pressed onto the surface of the discharge pipe.
 4. A method for manufacturing a discharge pipe for a fuel oil supply nozzle, the method comprising the steps of: forming an anchor spring by winding a spring wire into a spiral shape in a state in which a contact portion having a width and formed on one side in the direction of the axis of the spiral wire is situated inside; expanding an inside diameter on the contact portion side against a contracting force of the anchor spring; inserting a straight discharge pipe into an inside diameter side of the expanded anchor spring and thereafter releasing the contracting force to press and mount the anchor spring on an outer circumference surface of the discharge pipe; and bending the discharge pipe mounted with the anchor spring.
 5. The method for manufacturing a discharge pipe for a fuel oil supply nozzle according to claim 4, wherein the step of expanding the inside diameter of the anchor spring comprises fixing one end side of the anchor spring and rotating the other end side against the contracting force of the spring. 